In electrophoresis, electrically charged particles in a solution are caused to move in the presence of an applied electric field. The particles move toward the electrode of opposite electrical polarity. Gel slabs are often used to improve the resolving power of electrophoresis. Gel slabs have been widely adopted and allow for more stable separation and are often used in determining the molecular weights of proteins in biochemical studies.
One such electrophoresis device is disclosed in U.S. Pat. No. 5,632,877 entitled “Rapid Assembly Electrophoresis Cell For Slab Gels” issuing to Van Ata on May 27, 1997. Therein disclosed is an electrophoresis device containing an inner frame holding a gel slab. The inner frame is inserted into an outer clamping frame in which the pressure between the gel enclosure and the inner frame is maintained by a cam operated pressure plate. This entire assembly is then placed in a tank with a buffer solution.
Another electrophoresis device is disclosed in U.S. Pat. No. 6,193,868 entitled “Electrophoretic Separating and Blotting Apparatus” issuing Feb. 27, 2001 to Hsu. Therein disclosed is a frame held within a rack. The rack comprises a plurality of hold down elements adjusted to evenly press on a pressure block against glass plates. The rack is held within a positioning unit and placed in a casing or tank.
The use of pre-cast gel slabs contained in holder plates is widely accepted in electrophoresis. Pre-cast gel slabs are convenient and eliminate the need for a technician to make their own gel slabs. A casting system for making gel slabs is disclosed in U.S. Pat. No. 6,162,342 entitled “Rapid Assembly Casting System For Slab Gels” issuing Dec. 19, 2000 to Perez et al. Therein disclosed is a clamping frame for holding flat plates that serve as a mold for slab gels.
While the use of pre-cast gel slabs is convenient, they are often made in different sizes. For example, 8 cm×10 cm pre-cast gel slabs and 10 cm×10 cm pre-cast gel slabs are popular. However, these gel slabs have different thickness. Therefore, there are problems in mounting these different thickness pre-cast gel slabs in a single electrophoresis apparatus. Often, multiple electrophoresis apparatus are needed to accommodate the different size pre-cast gel slab holders that have different thicknesses. It is time consuming to adjust different electrophoresis apparatus that could accommodate multiple thicknesses of pre-cast gel slab holders. Additionally, it is often difficult to insert the pre-cast gel slab holders within an electrophoresis device without disassembling the electrophoresis device so as to insert the pre-cast gel slab holder. The complication of accommodating a variety of different gel slab holders having different thicknesses is often time costly and time consuming, preventing the efficient use of a laboratory technician's time.
Therefore, there is a need for an electrophoresis device that can quickly put in position and hold pre-cast gel slab holders having different thicknesses.